Particulate material storage bins are commonly used on farms for storing the grain. In some instances it is desirable for the grain bin to comprise a hopper bottom which is generally conical so as to taper downwardly and inwardly to the center to assist in center unloading of the grain bin. Such hopper bottoms may be formed integrally with the grain bin or may be formed as a separate component upon which a commercially available cylindrical bin is then supported.
Canadian patent application 2,008,299 by Weninger discloses an example of a grain bin hopper bottom in which the tapering cone portion terminates at a central bottom end spaced above the ground to receive an auger inlet therebelow. No means are provided for aeration through the hopper bottom.
Another known hopper bottom is disclosed in Canadian Patent Application 2,698,403 by Thiessen comprises a conical hopper portion which is surrounded by a cylindrical outer wall which supports the cone and the cylindrical bin walls thereabove. Ventilation of the grain in this hopper bottom is made available by enclosing the spaced between the hopper portion and the cylindrical outer wall to form a manifold which then directs air through perforated sections in the conical wall of the hopper portion. The manifold structure requires the use of the cylindrical outer wall. No means are provided for directing ventilation air into other parts of the grain bin other than through the perforated sections in the conical wall.
Further examples of grain drying through a hopper cone are disclosed in U.S. Pat. Nos. 5,604,994 by Annen et al. and 4,520,714 by Gullickson. In the prior art examples considerable ducting or multiple blowers are required to communicate ventilation air to the various perforated sections in the hopper cone.